Environment

Most of response time statistics are made with Dumbbench, you can install it using cpan.For example on Debian/Ubuntu:

$ sudo apt-get install cpanminus$ sudo cpanm Dumbbench

Unless specifically indicated otherwise all the tests are executed with a fully initialized instance (core extensions don't run anymore, SOLR index is fully up to date, etc.) and logged in with Admin user. Basically except for a few special tests we are using an instance that already been started and run until the proc is flat for some time.

Tests

Summary

"similar": difference is lower than 10%"slightly": difference is lower than 20%

Note that most of the speed related values are an average of very moving results, a lot of things is happening during a HTTP request and it's far from stable duration (that's why 10% may sounds a lot for something called "similar" but the variable can go up and down around 5% sometimes so 10% average is really not that much of a clear win). Dumbbench based tests are executed several times and the lowest result is selected.

Reload of Main.WebHome with UI

SOLR

Full SOLR reindex

Unit: seconds

Delete the data/solr folder, restart, load home page and calculate the time of activity of the SOLR index thread using Yourkit (Yourkit is slowing down a bit all that but what is important is the difference anyway).

7.4.5: 49

8.3: 52

SOLR sync

Only the thread determining what need to be indexed and not the actual indexing.

when index is empty

Unit: seconds

7.4.5: < 1

8.3: < 1

when there is nothing to do

Unit: seconds

7.4.5: < 1

8.3: < 1

Search

XWiki is doing nothing on background and everything is both in server and client cache already. Values are calculated using dumbbench (image/js/css/etc. resources are not taken into account).

Unit: milliseconds

Result of search finding lots of results

Login with Admin user and make sure hidden document display is enabled.